Publications
Filter Total Items: 1151
Magnetostratigraphic correlations of Permian-Triassic marine-to-terrestrial sections from China Magnetostratigraphic correlations of Permian-Triassic marine-to-terrestrial sections from China
We have studied three Permian–Triassic (PT) localities from China as part of a combined magnetostratigraphic, 40Ar/39Ar and U–Pb radioisotopic, and biostratigraphic study aimed at resolving the temporal relations between terrestrial and marine records across the Permo-Triassic boundary, as well as the rate of the biotic recovery in the Early Triassic. The studied sections from Shangsi...
Authors
J.M.G. Glen, S. Nomade, J.J. Lyons, I. Metcalfe, R. Mundil, P.R. Renne
Geophysical setting of western Utah and eastern Nevada between latitudes 37°45′ and 40°N Geophysical setting of western Utah and eastern Nevada between latitudes 37°45′ and 40°N
Gravity and aeromagnetic data refine the structural setting for the region of western Utah and eastern Nevada between Snake and Hamlin Valleys on the west and Tule Valley on the east. These data are used here as part of a regional analysis. An isostatic gravity map shows large areas underlain by gravity lows, the most prominent of which is a large semi-circular low associated with the...
Authors
Edward A. Mankinen, Edwin H. McKee
Cenozoic evolution of the abrupt Colorado Plateau–Basin and Range boundary, northwest Arizona: A tale of three basins, immense lacustrine-evaporite deposits, and the nascent Colorado River Cenozoic evolution of the abrupt Colorado Plateau–Basin and Range boundary, northwest Arizona: A tale of three basins, immense lacustrine-evaporite deposits, and the nascent Colorado River
In northwest Arizona, the relatively unextended Colorado Plateau gives way abruptly to the highly extended Colorado River extensional corridor within the Basin and Range province along a system of major west-dipping normal faults, including the Grand Wash fault zone and South Virgin–White Hills detachment fault. Large growth-fault basins developed in the hanging walls of these faults...
Authors
J. E. Faulds, Keith A. Howard, E. M. Duebendorfer
Digital coordinates and age of more than 13,000 foraminifers samples collected by Chevron Petroleum geologists in California Digital coordinates and age of more than 13,000 foraminifers samples collected by Chevron Petroleum geologists in California
The general location and age of more than 33,500 mostly foraminifer samples from Chevron surface localities in nearly 600 U.S. Geological Survey (USGS) 7.5' quadrangles from California were provided by Brabb and Parker (2003). Barren and non-diagnostic samples plus many that have no paleontologic information were omitted to provide a revised list for more than 27,000 of these samples by...
Authors
William T. Malmblorg, William B. West, Earl E. Brabb, John M. Parker
Newly discovered Paleocene and Eocene rocks near Fairfield, California, and correlation with rocks in Vaca Valley and the so-called Martinez Formation or Stage Newly discovered Paleocene and Eocene rocks near Fairfield, California, and correlation with rocks in Vaca Valley and the so-called Martinez Formation or Stage
Discovery of a 3-foot thick sandstone bed with abundant Turritellid gastropods of late Paleocene age about 4 miles northeast of Fairfield and on the southwest flank of Cement Hill, Solano County provides an opportunity to reevaluate the relationships of lower Tertiary formations in this part of California. Cement Hill is named for travertine deposits in and on top of sandstone of Late...
Authors
Earl E. Brabb, Donn Ristau, David Bukry, Kristin McDougall, Alvin A. Almgren, LouElla Saul, Annika Sanfilippo
Paleomagnetic study of late Miocene through Pleistocene igneous rocks from the southwestern USA: Results from the historic collections of the U.S. Geological Survey Menlo Park laboratory Paleomagnetic study of late Miocene through Pleistocene igneous rocks from the southwestern USA: Results from the historic collections of the U.S. Geological Survey Menlo Park laboratory
Seventy sites from the southwestern United States provide paleomagnetic results that meet certain minimum criteria and can be considered for the Time‐Averaged Field Initiative (TAFI). The virtual geomagnetic poles for these 70 units are circularly distributed, and their mean is nearly coincident with the rotational axis. When other published data for the southwestern United States are...
Authors
Edward A. Mankinen
Geology: Chapter 2 Geology: Chapter 2
No abstract available.
Authors
Richard G. Stanley, G. E. Weber
Structures controlling geothermal circulation identified through gravity and magnetic transects, Surprise Valley, California, northwestern Great Basin Structures controlling geothermal circulation identified through gravity and magnetic transects, Surprise Valley, California, northwestern Great Basin
No abstract available.
Authors
Jonathan M.G. Glen, Anne E. Egger, David A. Ponce
Quickly erupted volcanic sections of the Steens Basalt, Columbia River Basalt Group: Secular variation, tectonic rotation, and the Steens Mountain reversal Quickly erupted volcanic sections of the Steens Basalt, Columbia River Basalt Group: Secular variation, tectonic rotation, and the Steens Mountain reversal
The Steens Basalt, now considered part of the Columbia River Basalt Group (CRBG), contains the earliest eruptions of this magmatic episode. Lava flows of the Steens Basalt cover about 50,000 km2 of the Oregon Plateau in sections up to 1000 m thick. The large number of continuously exposed, quickly erupted lava flows (some sections contain over 200 flows) allows for small loops in the...
Authors
Nicholas A. Jarboe, Robert S. Coe, Paul R. Renne, Jonathan M. G. Glen, Edward A. Mankinen
Millimeter-scale geologic mapping using field spectroscopy techniques Millimeter-scale geologic mapping using field spectroscopy techniques
No abstract available.
Authors
David C. Buesch, Daniel E. Ragona, Mark C. Helmlinger
Mineral deposit densities for estimating mineral resources Mineral deposit densities for estimating mineral resources
Estimates of numbers of mineral deposits are fundamental to assessing undiscovered mineral resources. Just as frequencies of grades and tonnages of well-explored deposits can be used to represent the grades and tonnages of undiscovered deposits, the density of deposits (deposits/area) in well-explored control areas can serve to represent the number of deposits. Empirical evidence...
Authors
Donald A. Singer
The geology and tectonic history of Santa Clara County The geology and tectonic history of Santa Clara County
No abstract available.
Authors
M. Clark Blake, C. M. Wentworth